Apparatus for drilling wells



Filed Sept. 6, 1966 INVENTOR.

ATTORNEY;

United States Patent 16,043/ 66 US. Cl. 175-173 Int. Cl. E21b 21/00 3Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to anapparatus for drilling wells under circulation of drilling mud,including a string of hollow rods allowing passage of drilling mudtherethrough, a tubular member having drilling tools connected at thelower end thereof and in telescoping relation with respect to saidstring, cable means connected with said tubular member and extendingalong said string beyond said well, driving means for reciprocating saidtubular member in a direction parallel to said string and cooperatingwith said cable means, a rotary table for imparting intermittent angularmovement to said drilling tools about the axis of said string, a pumpfor circulating the drilling mud and having its suction pipe connectedwith said string of hollow rods.

The present invention relates to an apparatus for drilling wells orholes in general in grounds of any nature and consistency.

It is known in the art of well drilling to support the walls of the wellby means of colloidal drilling muds, such as mortar containing drillingmuds.

The bore hole Or well is always kept full with drilling mud or mortarmuds, so that a constant direct supporting action is exerted on thewalls thereof.

The known systems for drilling, wells, holes, and the like use toolswhich, by exerting a cutting action on the ground, disintegrate the sameand carry it up to the top of the bore hole or such tools have only thetask of disintegrating the ground, while the ground thus disintegratedis carried to surface by drilling muds.

In practice, it has been found that such systems have numerousdisadvantages as a consequence of the way the tools act on the ground.

Systems utilizing 'tOOls such as clamshell buckets, scrape buckets andthe like, are generally very slow and encounter problems in cuttingcompact or immersed grounds, while when drilling muds are provided it isdifficult to control the removal of waste or cuttings.

Summary of the invention An object of the present invention is toprovide an apparatus adapted to allow a quick drilling of bore holeseven and particularly in hard or compact ground, such as rocks.

Another object of the present invention is to provide an apparatus whichwill allow easy to drill wells of considerable depth.

A further object of the present invention is to provide an apparatuswhich will allow to obtain wells, holes, cuttings and the like havingcompletely vertical side walls.

A still further object of the present invention is to provide anapparatus of low cost.

These and still other objects are attained by an apparatus for drillingwells under circulation of drilling mud, including a string of hollowrods allowing passage of drilling mud therethrough a tubular memberhaving drilling tools connected at the lower end thereof and intelescoping relation with respect to said string, cable means connectedwith said tubular member and extending along said 3,420,321 PatentedJan. .7, 1969 string beyond said well, driving means for reciprocatingsaid tubular member in a direction parallel to said string andcooperating with said cable means, a rotary table for impartingintermittent angular movement to said drilling tools about the axis ofsaid string, a pump for circulating the drilling mud and having itssuction pipe connected with said string of hollow rods and wherein theimprovement comprises a sleeve member surrounding a length of saidstring and rigid and coaxial therewith, said sleeve member having anouter diameter less than the inner diameter of said tubular member,cooperating longitudinal guideway means on the outer periphery of saidsleeve member and on the inner periphery of said tubular lar memberallowing a telescoping motion between said sleeve and said tubularmember and preventing relative angular motions therebetween, and whereinsaid drilling tools comprise a first group of symmetrically arranged bitmembers having a pin-like shape and extending radially in first radialplanes transverse to each other and defining a first drilling peripherywith a diameter greater than said tubular member, and a second group ofbit members extending radially in other radial planes forming an anglewith said first radial planes, said second group of bit membersextending longitudinally beyond the longitudinal extension of said firstgroup of bit members and defining a second drilling periphery having adiameter less than the diameter of said first drilling periphery.

Brief description of the drawing Further features and advantages of thedevice according to the invention will now be more apparent from thedescription of an embodiment given by way of a nonlimiting example inconjunction with the accompanying drawing, in which:

FIG. 1 is a fragmentary sectional view of the apparatus according to theinvention;

FIG. 2 is a bottom view of the drilling tools used; and

FIG. 3 is a sectional view taken along line A-A' of FIG. 1.

Description of the preferred embodiment Referring to the drawing, thebore hole being drilled is indicated at 1. A working table is indicatedat 2 while at 3 there is indicated a suction unit with an intake line 4and a discharging line 5. A rotary table 6 which is supported on theworking table 2 can be driven to rotate both in clockwise andcounterclockwise directions and to which a string of hollow rods or pipesections 7 is connected.

At the lower end of said string 7, there is arranged a hollow rod orsleeve member 8 provided with outer vertical longitudinal guideways 9.

Vertically moveable along said rod 8 is a drilling head 10, which isconnected in a known way thereto, such as by means of a bush 13a andcounter-bush 13b, and is internally provided with longitudinal seatingsor grooves 11 designedto cooperate with the corresponding guideways 9.

The drilling head 10 has a tubular member 12 and a pin-like structure13.

Said structure 13 is provided with four pin-like supporting members 14,at the ends of which hits 14a and 15a are provided integral therewithand defining a first group of bits.

Four bits 15 defining a second group of bits are provided at the lowerand central portion of the head 10. The bits 15a are radially arrangedon each member 14. In the figures, the cutting edges of the drillingtools are shown by thin and parallel lines defining a wedge like shape(see FIG. 2).

As may be best seen from FIG. 2 of the drawing the bits a of the firstgroup of bits extend radially from the axis of the string in directionsperpendicular to each other and the bits 15' of the second group of bitsalso extend radially to the axis of the string in directionsperpendicular to each other and inclined with rcspect to the radialdirections of the first group of bits. In addition, the second group ofbits extends longitudinally beyond the bits of the first group. It mayalso be seen from the drawing that the bits 15a and 14a form together aT-like shape in which the bit 15a corresponds to the web portion of theT-like shape and the bit 14a corresponds to the flange portion of theT-shape.

Two cables 16 and 17, are connected to the upper portion of the tubularmember 12. Through lugs 12a and to an upper common drive cable runningover pulleys 19 and 20 of a crane structure 18 and terminating in acapstan 21.

A decantation tank 22 is adjacent the bore hole and is in communicationthereto by a return duct 23 for drilling mud.

The operation is as follows.

By means of capstan 21, the drilling head 10 is raised to some extentvertically along the rod 8 and then allowed to fall by gravity onto thebottom to be drilled.

Of course, the bore hole is always kept full with drilling mud.

Upon each fall the bottom of the hole is further disintegrated by a toand from rotary motion of the drilling head about its vertical axis,preferably through an angle at least of 90, owing to the action of therotary table 6.

The suction unit 3 conveys the disintegrated material up to the groundlevel and into a decantation tank 22 through the string of hollow rods7, conduit 4 and conduit 5. In this tank 22, the cuttings and stoneswill deposit on the bottom while the drilling fluid will return to thebore hole 1 via the return duct 23.

It should be noted that tank 22 may be substituted by filtering devices,which are well known in the art, thus an illustration thereof beingconsidered not necessary.

Furthermore the intake conduit 4, as known, could consist of a hoseinstead of the rigid duct 4 slidably and coaxially connected to theupper part of the hollow rods string 7.

I claim:

1. An apparatus for drilling wells under circulation of drilling mud,including a string of hollow rods allowing passage of drilling mudtherethrough a tubular member having drilling tools connected at thelower end thereof and in telescoping relation with respect to saidstring, cable means connected with said tubular member and extendingalong said string beyond said well, driving means for reciprocating saidtubular member in a direction parallel to said string and cooperatingwith said cable means, a rotary table for imparting intermittent angularmovement to said drilling tools about the axis of said string, a pumpfor circulating the drilling mud and having its suction pipe connectedwith said string of hollow rods and wherein the improvement comprises asleeve member surrounding a length of said string and rigid and coaxialtherewith, said sleeve member having an outer diameter less than theinner diameter of said tubular member, cooperating longitudinal guidewaymeans on the outer periphery of said sleeve member and on the innerperiphery of said tubular member allowing a telescoping motion betweensaid sleeve and said tubular member and preventing relative angularmotions therebetween, and wherein said drilling tools comprise a firstgroup of symmetrically arranged bit members having a pin-like shape andextending radially in first radial planes transverse to each other anddefining a first drilling periphery with a diameter greater than saidtubular member, and a second group of bit members extending radially inother radial planes forming an angle with said first radial planes, saidsecond group of bit members extending longitudinally beyond thelongitudinal extension of said first group of bit members and defining asecond drilling periphery having a diameter less than the diameter ofsaid first drilling periphery.

2. An apparatus according to claim 1, wherein said first group of bitmembers has bits facing the bottom of the well each of which has wedgelike cutting edges defining the shape of a T with the web portion of theT extending in radial direction and the flange portion of the Tperipherally arranged.

3. An apparatus according to claim 1, wherein said second group of bitmembers has bits each of which has radially extending wedge like cuttingedges.

References Cited UNITED STATES PATENTS 1,562,449 11/1925 Herrin 2621,709,074 4/1929 Herrin 175262 2,911,192 11/1959 Boucher 17556 3,012,62112/1961 Baud et a1 175213 3,024,853 3/1962 Herbold 175213 CHARLES E.OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner.

US. Cl. X.R.

